Speeds and Feeds- Spiral Router Bits

Recommended Feeds & Speeds for Solid Carbide Router Bits

Use the following chip load chart as a starting point only. Feeds and speeds may vary due to machining limitations. The chart applies if the cutting depth is equal to the bit diameter.

  • For cuts depth that is 2 times the bit diameter, reduce chip load by 25%.
  • For cut depth that is 3 times the bit diameter, reduce the chip load by 50%
  • Example 1: 1/2" spiral compression bit with a recommended chip load of .02; with a cutting depth of 1", the chip load should be .02 x .75( a 25% reduction) = .015
  • Example 2: 3/8" spiral compression bit with a recommended chip load of .018; with a 1 1/8" cutting depth (3 times 3/8"), the chip load should be .018 x .5 = .009

 

 
Cutting
Material

MDF/

Particle

Board
Hardwood
Softwood

Soft

Plastic

Hard

Plastic
Plywood
Tool 		1/8"
.004"-.007"
.002"-.004"
.003"-.005"
.003"-.005"
.002"-.004"
.003"-.005"
Chip
Diameter
1/4"
.012"-.015"
.005"-.007"
.006"-.008"
.006"-.009"
.005"-.008"
.006"-.009"
Load
3/8"
.017"-.019"
.013"-.015"
.015"-.017"
.009"-.011"
.008"-.010"
.015"-.018" 		Range
1/2"
.020"-.025"
.017"-.019"
.019"-.021"
.011"-.014"
.010"-.013"
.018"-.021"

Match the feed and speed to the selected chip load: 

  • To determine the feed and speed to match the chip load for your application, use one of the formulas below that coincide with your preferred variable.
  • Feed rate is measured in inches per minute. 

 

Follow these steps to achieve the best tool life and quality:

  • use the recommended chip load and increase feed rate until the quality is not acceptable
  • decrease the feed rate until preferred part finish is reached
  • decrease RPM until part finish weakens
  • increase RPM until finish is acceptable

These steps will attain the greatest chip load possible, which will result in a longer tool life, as well as avoiding excessive heat.

 

***Note: The information provided is a starting point and does not guarantee against tool breakage.***